Personnel appointed by the tax collection authorities concerned or the Taxation Administration of the Ministry of Finance shall conduct inquisition ex officio into evidence and shall take into consideration circumstances both advantageous and disadvantageous to the party. The means of investigation must be legal, necessary, and minimizing invasiveness into the basic rights of taxpayers.
The tax collection authorities shall have the burden of proof of constituent elements and facts of tax assessment or punishment, except where explicitly specified in other laws.
The evidence obtained from illegal investigation of personnel appointed by the tax collection authorities concerned or the Taxation Administration of the Ministry of Finance shall not be used as the basis of tax assessment or penalty, except that the evidence is a minor offence and the exclusion of utilization of that evidence apparently brings violation of public interest.
Before the tax collection authorities make a tax assessment or order a penalty, they shall give the taxpayer the chance to offer an opinion statement, except for the circumstances set in Article 103 of the Administrative Procedure Act or proviso of Article 42 of the Administrative Penalty Act.
The tax assessment or penalty made by the tax collection authorities shall be in writing and state therein its reason and legal basis, except for the circumstances set in Article 97 of the Administrative Procedure Act.
The penalties of the preceding paragraph shall not become effective unless in written notifications or public notices. If there is no written notice stating therein the reason, the amendment is only allowed before the administrative appeal procedure is concluded; if no administrative appeal procedure is required, such acts of remedy may be effected only before a suit is filed in the administrative court.